Future neutrino experiments The roadmap and a few

Future neutrino experiments The road-map… and a few itineraries Three family oscillations Low energy Super-beam: JHF CERN-SPL … and beta-beam Neutrino Factory R&D and new developments: EMCOG, MICE, ring cooler BENE and design studies Conclusions

Physics with accelerators can be divided broadly into two classes 1. Physics at the high energy frontier (LHC, NLC, CLIC). Presently this searches experimental confirmation of our explanations for the electroweak symmetry breaking. Higgs, Supersymmetry etc. . 2. Precision measurements of particle properties and rare processes B factories, neutrino physics, m-> e g, tests of QED and QCD Neutrinos are fascinating because it was recently discovered that they have a mass and… That their masses are VERY different from those of the other particles. The mass and mixing of neutrinos seem to originate at very high energies (see-saw mechanism) Today we will describe new types of accelerators for neutrino physics (and more): NEUTRINO FACTORIES and BETA BEAMS

neutrino definitions the electron neutrino is present in association with an electron (e. g. beta decay) the muon neutrino is present in association with a the tau neutrino is present in association with a muon tau (pion decay) (W tn decay) these flavor-neutrinos are not (as we know now) quantum states of well defined mass (neutrino mixing) the mass-neutrino with the highest electron neutrino content is called n 1 the mass-neutrino with the next-to-highest electron neutrino content is n 2 the mass-neutrino with the smallest electron neutrino content is called n 3

Neutrino Oscillations (Quantum Mechanics lesson 5) source detection propagation in vacuum -- or matter L weak interaction produces ‘flavour’ neutrinos e. g. pion decay p mn ¦n m > = a ¦n 1 > + b ¦n 2 > + g ¦n 3 > weak interaction: (CC) Energy (i. e. mass) eigenstates propagate ¦n (t)> = a ¦n 1 > exp( i E 1 t) + b ¦n 2 > exp( i E 2 t) + g ¦n 3 > exp( i E 3 t) t = proper time L/E n m N m- C or n e N e- C or nt N t- C P ( m e) = ¦ < ne ¦ n (t)>¦ 2

Lepton Sector Mixing Pontecorvo 1957

Oscillation Probability Hamiltonian= E = sqrt( p 2 + m 2) = p + m 2 / 2 p for a given momentum, eigenstate of propagation in free space are the mass eigenstates!

To complicate things further: matter effects elastic scattering of (anti) neutrinos on electrons ne, m, t Z e- e- ne W- e- ne e- all neutrinos and anti neutrinos do this equally only electron neutrinos ne e. W- These processes add a forward amplitude to the Hamiltonian, which is proportional to the number of elecrons encountered to the Fermi constant and to the neutrio energy. e. The Z exchange is diagonal in the 3 -neutrino space this does not change the eigenstates only electron anti- neutrinos The W exchange is only there for electron neutrinos It has opposite sign for neutrinos and anti-neutrinos (s vs t-channel exchange) D= 2 2 GF ne. En THIS GENERATES A FALSE CP VIOLATION ne

D= 2 2 GF ne. En This is how YOU can solve this problem: write the matrix, diagonalize, and evolve using, Hflavour base= This has the effect of modifying the eigenstates of propagation! Mixing angle and energy levels are modified, this can even lead to level-crossing. MSW effect antineutrino nm, t neutrino m 2 n ne En or density oscillation is further suppressed oscillation is enhanced for since T resonance… enhances oscillation neutrinos if Dm 21 x >0, and suppressed for antineutrinos if Dm 21 x <0, and suppressed for neutrinos asymmetry uses neutrinos it is not affected